This invention relates to a rotary seal.
There are many circumstance in which a mechanism that is mounted to a stationary member interacts with a rotary member. It might be necessary or desirable to protect the mechanism from contact with foreign matter, such as dust, particularly when the rotary member is rotating at low speed or is stationary. The mechanism may be protected from dust by a housing having a rotary part attached to the rotary member and a stationary part attached to the stationary member.
In accordance with a first aspect of the invention there is provided a rotary seal comprising an annular seal body and an annular lip attached to the seal body and extending radially outwards from the seal body, the annular lip having a stem and a tip and being attached to the seal body in a manner allowing deflection of the lip relative to the seal body.
In accordance with a second aspect of the invention there is provided a rotational assembly including a stationary part, a rotary part mounted to rotate relative to the stationary part about an axis, and an annular seal attached to the rotary part and coaxial therewith, the seal comprising a seal body and a lip attached to the seal body and extending outwards from the seal body, the lip having a stem and a tip and being attached to the seal body in a manner allowing deflection of the lip relative to the seal body, and wherein the tip engages the stationary part when the rotary part is not rotating or is rotating at a low speed and tends to lift away from the stationary part when the rotary part is rotating at higher speed.